The enzymatic reactions involved in the degradation of uric acid by Clostridium cylindrosporum and Clostridium acidi-urici will be investigated with particular reference to formyltetrahydrofolate synthetase and other folate-requiring enzymes. The properties of the formate activating enzyme from the clostridia will be compared with the enzyme isolated from sheep liver and yeast with respect to activity of the different folate polyglutamate derivatives, the reversibility of the reaction, the effect of monovalent cations on the reaction, and the molecular structure of the enzyme isolated from the two sources. The properties of the eucaryotic multiheaded enzyme, Formyl-Methenyl-Methylenetetrahydrofolate Synthetase (Combined), will be determined and compared to those of the equivalent system composed of the purified separable enzymes isolated from the purine-fermenting bacteria. We will attempt to purify the enzymes involved in the biosynthesis of the polyglutamyl derivatives of tetrahydrofolate from the purine-fermenting clostridia. Purification of the enzyme catalyzing the folate-mediated biosynthesis of tRNA ribothymidine will be continued, and the substrates and products of the reaction and the properties of the enzyme will be determined. We will attempt to determine the basis of the specificity shown by Bacillus subtilis and other Gram-positive ribosomes in the translation of cellular messenger-RNA derived from Bacillus subtilis and other Gram-positive organisms, and will examine the process involved in the translation of message derived from the bacillus phage, phi-29. The effect of ribosomal protein SI on the ability of Bacillus subtilis ribosomes to translate cellular messages as well as the phage RNA messages will be examined. We will continue our efforts to purify clostridial ferredoxin messenger-RNA and the physiological factors affecting the formation of components required for the synthesis of ferrodoxin will be examined.